The bonding of elastomeric materials such as polyvinyl chloride to a glass substrate is well known and is utilized in many industries involving devices which require the interface of an elastomeric material and glass parts or components. The vinyl chloride polymer, or other elastomer, is typically injection molded or applied as a hot melt to a glass substrate that has been coated with an appropriate adhesive. In many applications, in order to obtain an effective bond between the elastomer and glass surface, preheating of the adhesive after application to the glass surface is required.
One application, which is gaining popularity and represents a new concept in automotive design, is the production of modular windows. Modular windows can significantly reduce the drag coefficient of an automobile which employs such a window. Modular windows are prepared by a one-step molding process wherein the edge of a glass component is bonded within a polymeric gasket. The polymeric gasket is typically made of a material such as reaction injection molded (RIM) urethane or polyvinyl chloride.
One example of an effort to improve the adhesion of vinyl polymers to glass surfaces is disclosed in U.S. Pat. No. 3,998,985, which relates to the incorporation of certain polyaminosilane compounds within the vinyl polymer to be bonded. Specifically, the vinyl polymer is mixed with a combination of a polyaminosilane and a primer which contains an epichlorohydrin-Bisphenol A resin, N-aminoethyl-gamma-aminopropyltrimethoxy silane, ethyleneglycolmonomethyl ether, and ethyleneglycolmonoethylether acetate.
Further examples of vinyl polymer-glass adhesives are disclosed in U.S. Pat. No. 3,666,539, which discloses epoxy reactive silanes which act as coupling agents for adhering various polymers to glass; U.S. Pat. No. 3,362,843, which discloses a mixture of an aminoalkylalkoxy silane and an epoxy resin-methyl methacrylate primer; and U.S. Pat. No. 3,734,763, which discloses the use of N-[beta-(N'-paravinylbenzyl)-aminoethyl]gamma-aminopropyltrimethoxy silane hydrochloride as a vinyl polymer-glass coupling agent.
Although previously developed vinyl polymer-glass adhesives such as those disclosed above work reasonably well in certain applications, it would be desirable to develop a vinyl polymer-glass adhesive which would be particularly adaptable to applications involving the production of modular windows. Such an adhesive should be capable of providing a weather-resistant bond without the requirement of preheating the adhesive-coated glass surface prior to bonding of the elastomeric material.